The purpose of this invention is to provide thermal insulation for people and objects. More specifically, the invention addresses, but is not limited to, keeping divers warm while diving in dry suits in cold water.
Currently dry suits attempt to keep divers warm by first keeping them dry, and second surrounding them with a blanket of air and insulated underwear.
The problem with these suits is that, while a diver is in the water, air seeks the highest point towards the surface, because the deepest portion of a diver has the greatest exterior water pressure. That causes the insulating materials such as Cloroprene and Thinsulate to compress against the skin. Cloroprene and Thinsulate are good insulators because they trap voids of air in between their respective materials, but when these materials are compressed the voids of air are squeezed out, causing them to lose their insulating qualities and allowing heat transfer from the diver to occur more readily.
Currently dry suits are designed to provide three layers of insulation. First, an outer layer which is waterproof is usually fabricated of Neoprene or Chloroprene. The suits are usually filled with air to provide the second layer of insulation. Finally, thermal underwear such as that made from Thinsulate is worn to provide more insulation.
The problem with that design is that, when divers get into water, there is more outside pressure on the deepest portion of the diver than there is on the portions closer to the surface. That causes the air contained in the suit to rise toward the water surface. That also causes the material located at the deepest portion of the diver's suit to be squeezed against the diver's skin. The layers of insulation described above all work by trapping pockets of air in their respective materials. When those materials are compressed, air is expressed and their insulation qualities decrease dramatically. When a diver descends, those materials compress more with depth, and less effective insulation results. Also, the air that is contained in the suit rises, allowing the deepest portion of the diver to have the thinnest layer of insulation and become the coldest. The problem is especially noticeable in extremities such as feet and legs, which quickly become cold by conduction as insulating air within the suit is pressed upward by the pressure differential. Air in gloves is squeezed up toward shoulders or is released by valves at backs of gloves. Heat is quickly lost through conduction.